IIS 5 & IIS 6
Application Pool memory leak?
Last post Apr 12, 2018 08:36 AM by zaqxen
Sep 04, 2014 09:21 AM|martiendejong2008|LINK
One of the ASP.NET websites that I am hosting in an IIS6 environment on a Windows 2003 server has this problem where every now and then the application pool has to be restarted because the site starts to show unexpected behavior.
The following things happen:
These problems appear on the same pages consistently. When I look into the code there is nothing irregular there.
When the application pool is restarted the application behaves normally again.
I had these results only on the production environment and never on the development or staging.
I was unable to find anything useful on the net, but I suspect that something in the application is causing it to become corrupted in this way.
The application does the following:
If someone has an idea what may be causing this I would be really grateful because I am completely stuck on this for months and so are my colleagues.
Thanks a lot for any replies!
Sep 05, 2014 02:04 AM|Pengzhen Song - MSFT|LINK
I suggest that you can troubleshoot IIS Performance Issues or Application Errors using LogParser. This troubleshooter will help you analyze IIS log files in an effort to determine the cause when an application that is hosted on IIS is failing or experiencing
For more information, you can refer here
#Fix the 3 silent performance killers for IIS / ASP.NET apps
Sep 05, 2014 03:03 AM|martiendejong2008|LINK
Thank you for taking the time to investigate my issue. I used the Log Parser and I see the following results:
Most pages are HTTP 200, and even when the page's contents are completely messed up there is no error it gets served normally.
An occasional page gives HTTP 404, these files or pages do exists but it appears that the webserver at that time is unable to serve it.
An occasional HTTP 500, when there is an SQL Exception in the page.
And when the application pool is recycled everything works fine again.
Just to be clear there is NO dynamic SQL in the pages with give an SQL exception, just static queries with some parameters.
The pages that give a 404 error are also 'normal' pages, some are even static content, like stylesheets or images. They just aren't served anymore when the application goes to error mode.
I still don't have a clue.
Sep 09, 2014 03:06 AM|martiendejong2008|LINK
Is there anyone who can help me with this?
Did I not supply enough information? If I need to supply more info please tell me what I should provide.
Sep 10, 2014 02:49 AM|martiendejong2008|LINK
The event log says this: (sorry it's in dutch)
Gebeurteniscode: 3005 Gebeurtenisbericht: Er is een onverwerkte uitzondering opgetreden. ... ... Procesinformatie: Proces-id: 7484 Procesnaam: w3wp.exe Uitzonderingsinformatie: Uitzonderingstype: ArgumentException Uitzonderingsbericht: De kolom description
hoort niet bij de tabel . bij System.Data.DataRow.GetDataColumn(String columnName) bij System.Data.DataRow.get_Item(String columnName) bij ... removed the rest for privacy reasons) ...
Basically what it says is that the column does not belong to the table that is returned by an SQL query. This happens for various queries that have nothing strange in them (just queries like SELECT id, name, description FROM roles WHERE userid=@id)
I did find a solution by catching the exception and then resetting the application pool in the website itself by using this code:
Public Sub ResetAppPool(appPool As String)
entry = New DirectoryEntry("IIS://localhost/W3SVC/AppPools/" + appPool)
Of course this is a workaround and I am still curious what is happening here and what can be done about it.
Oct 13, 2014 06:02 AM|martiendejong2008|LINK
Another bump... I am still looking for the answer to this problem. The application pool is resetting multiple times a day now and it really is a problem for our customers. I still do not have a clue on how to solve this. If anyone could point me in a direction
that would be great!
Apr 12, 2018 08:36 AM|zaqxen|LINK
Things to look at:
Hope this help or somehow minimizes its occurrence.